JP6509341B2 - Bearing replacement method for X-ray CT system - Google Patents

Description

  The present invention relates to an X-ray CT apparatus in which a rotating body mounted with an X-ray source and the like is rotatably supported by a stationary frame via a bearing, and a bearing replacement method thereof.

  In a scanner gantry of a conventional X-ray CT apparatus, a rotating disk on which an X-ray tube and an X-ray detector are mounted is rotatably supported by a stationary frame via a bearing (see, for example, Patent Documents 1 and 2) .

JP, 2011-167351, A JP, 2013-255753, A

  In the conventional X-ray CT apparatus, the rotating part including the rotating disk and the mounted object is a heavy object exceeding 500 kg, and shipping inspection of a single bearing simulating actual use in a scanner gantry is not easy. Therefore, after actually being incorporated into the scanner gantry, there may be an abnormality in rotational resistance or an abnormal noise that can not be found in the shipping inspection.

  In addition, with the high-speed rotation of the X-ray CT apparatus, the load on the bearing may be increased and the life of the bearing may be shortened. As described above, it may be necessary to replace the bearing at the site where the X-ray CT apparatus is installed, such as when abnormal rotation resistance or abnormal noise occurs, or when the life becomes short due to high speed rotation.

  However, in the conventional X-ray CT apparatus, the bearing is disposed between the rotating disk and the stationary frame, and the bearing can not be removed unless the rotating disk is separated from the stationary frame. For this reason, bearing replacement work becomes very large, requiring a large space for removing the rotating disk and a large amount of working time.

  The present invention has been made to solve the problems as described above, and it is an object of the present invention to obtain an X-ray CT apparatus in which bearings can be easily replaced with a simple configuration.

  The X-ray CT apparatus according to the present invention is rotatably supported by a stationary frame and a stationary frame, and a bearing interposed between the stationary frame and the rotating body, the rotating body rotating around the subject. The rotating body has an opposing portion facing the end face of the stationary frame orthogonal to the axial direction of the rotating body via a gap, and the opposing portion is attached to the rotating body at the time of replacing the bearing. A plurality of through holes through which at least one of a plurality of gap holding members that are held against the end surface to hold a gap and a plurality of rotating body fixing screws that fix the rotating body to the stationary frame at the time of bearing replacement Is provided, and the end face is provided with a plurality of rotating body fixing screw holes into which the rotating body fixing screws passed through the through holes when the bearing is replaced.

  According to the X-ray CT apparatus of the present invention, the bearing can be easily replaced with a simple configuration.

Front view showing a scanner gantry portion of an X-ray CT apparatus according to a first embodiment of the present invention Sectional view along line II-II in FIG. 1 Rear view showing the scanner gantry portion of FIG. 1 Sectional view along the IV-IV line of FIG. 1 Sectional view along line V-V in FIG. 1 FIG. 7 is a perspective view showing the gap maintaining member according to the first embodiment. A cross-sectional view showing a state in which a gap holding member is attached to the rotating body shown in FIG. Sectional drawing which shows the state which removed the drive pulley from the bearing of FIG. 4 Sectional drawing which shows the state which removed the driving pulley from the bearing of FIG. Sectional drawing which shows the state which removed the bearing from the cylindrical part of FIG. Sectional drawing which shows the state which removed the bearing from the rotary body 5 of FIG. Principal part sectional view of X-ray CT apparatus according to Embodiment 2 of this invention Sectional view showing a modification of the gap holding member

  The X-ray CT apparatus according to the present invention is rotatably supported by a stationary frame and the stationary frame, and is interposed between a rotating body that rotates around a subject, the stationary frame, and the rotating body. The rotating body has an opposing portion facing the end face of the stationary frame orthogonal to the axial direction of the rotating body via a gap, and the opposing portion is the rotating body And at least one of a plurality of gap holding members for holding the gap against the end face and a plurality of rotating body fixing screws for fixing the rotating body to the stationary frame A plurality of through holes are provided, and the end surface is provided with a plurality of rotating body fixing screw holes into which the rotating body fixing screws passed through the through holes are screwed.

Further, each of the gap holding members is constituted by a male screw, and each of the through holes is constituted by a screw hole into which the gap holding member is screwed.
Further, each of the gap holding members is cylindrical, and a hole for passing the rotating body fixing screw is provided at the center.

  The bearing is fixed to the stationary frame using a plurality of stationary frame side fasteners, and is fixed to the rotating body using a plurality of rotating body side fasteners, and the stationary frame side fastener And the said rotation body side fastener is each fastened to the said stationary frame and the said rotation body from the same direction of the axial direction of the said rotation body.

  Further, the gap holding member and the rotating body fixing screw are configured to pass through the through hole from the direction opposite to the fastening direction of the stationary frame side fastener and the rotating body side fastener.

  Further, in the bearing replacement method for an X-ray CT apparatus according to the present invention, a stationary frame, a rotary body rotatably supported by the stationary frame, which rotates around a subject, the stationary frame, and the rotary body A bearing interposed therebetween, a plurality of stationary frame side fasteners fixing the bearing to the stationary frame, and a plurality of rotating body side fasteners fixing the bearing to the rotating body The rotating body has an opposing portion opposed to the end face of the stationary frame, which is orthogonal to the axial direction of the rotating body, with a gap, and a plurality of through holes are provided in the opposing portion. And a plurality of rotating body fixing screw holes are provided on the end face, and a plurality of gap holding members are attached to the opposite portion in a state of passing through at least a part of the through holes and contacting the end face. By The step of holding the gap, and the step of fixing the rotating body to the stationary frame by screwing a plurality of rotating body fixing screws into the rotating body fixing screw holes through at least a part of the through holes. Removing the stationary frame side fastener and the rotating body side fastener, and replacing the existing bearing with a new bearing, the stationary frame side fastener and the rotating body side fastener using the new bearing as a stationary frame and the stationary frame side fastener The process of fixing to a rotary body and the process of removing the said gap | interval holding member and the said rotary body fixed screw are included.

  Further, each of the gap holding members has a cylindrical shape in which a hole is provided at the center, and the rotating body fixing screw is screwed into the rotating body fixing screw hole through the hole of the gap holding member.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Embodiment 1
1 is a front view showing a scanner gantry portion of an X-ray CT apparatus according to Embodiment 1 of the present invention, FIG. 2 is a sectional view taken along line II-II in FIG. 1, and FIG. 3 is a scanner gantry portion in FIG. It is a rear view.

  In FIGS. 1 to 3, the stationary frame 1 is supported by a pair of stands 2 a and 2 b. The stationary frame 1 also includes a main frame 3 and a pair of side frames 4 a and 4 b disposed on both sides of the main frame 3. The main frame 3 has a flat plate portion 3a and a cylindrical portion (center frame) 3b fixed to the flat plate portion 3a.

  On the cylindrical portion 3b, a disk-shaped rotating body (rotary disc) 5 which rotates around a subject (not shown) is rotatably supported. A bearing 6 is interposed between the cylindrical portion 3 b and the rotating body 5. A driving pulley 7 for rotating the rotating body 5 is attached to the bearing 6.

  An X-ray tube 8 as an X-ray source, an X-ray detector 9, a high voltage generator 10, an inverter 11, a cooler 12, and a controller 13 are mounted on the rotating body 5. The X-ray tube 8 irradiates the subject with X-rays. The X-ray detector 9 is opposed to the X-ray tube 8 and detects X-rays transmitted through the subject.

  The X-ray CT apparatus is an image reconstruction apparatus that reconstructs a tomographic image of the subject based on the X-ray dose detected by the scanner gantry unit, the bed on which the subject is placed, and the X-ray detector 9 shown in FIG. And an image display device etc. for displaying a tomographic image reconstructed by the image reconstruction device.

4 is a cross-sectional view taken along the line IV-IV of FIG. 1, and FIG. 5 is a cross-sectional view taken along the line VV of FIG.
The bearing 6 has an outer ring 6a fixed to the stationary frame 1, an inner ring 6b fixed to the rotating body 5, and a plurality of balls 6c interposed between the outer ring 6a and the inner ring 6b. .

  The outer ring 6 a is fixed to the stationary frame 1 using a plurality of stationary frame side fasteners 14. As each stationary frame side fastener 14, a bolt is used. The outer ring 6a is provided with a plurality of outer ring fastener holes 6d through which the stationary frame side fastener 14 passes. The cylindrical portion 3b is provided with a plurality of stationary frame side fastener screw holes 3c into which the stationary frame side fastener 14 is screwed.

  The inner ring 6 b is fixed to the rotating body 5 using a plurality of rotating body side fasteners 15. As each rotating body side fastener 15, a bolt is used. The inner ring 6 b is provided with a plurality of inner ring fastener holes 6 e through which the rotating body side fastener 15 passes. The rotating body 5 is provided with a plurality of rotating body side fastener screw holes 5 a into which the rotating body side fastener 15 is screwed.

  The driving pulley 7 is fixed to the inner ring 6 b using a plurality of pulley fasteners 16. A bolt is used as each pulley fastener 16. The driving pulley 7 is provided with a plurality of pulley fastener holes 7 a for passing the pulley fasteners 16. The inner ring 6b is provided with a plurality of pulley fastener screw holes 6f into which the pulley fastener 16 is screwed.

  The stationary frame side fastener 14, the rotating body side fastener 15, and the pulley fastener 16 are each formed in the same direction as the axial direction of the rotating body 5, that is, from the rear side of the stationary frame 1, the cylindrical portion 3b, the rotating body 5, and the inner ring. It is signed to 6b. Therefore, the stationary frame side fastener 14, the rotating body side fastener 15, and the pulley fastener 16 are disposed in parallel with the axial direction of the rotating body 5.

  The stationary frame 1 and the rotating body 5 are fixed to the same side of the bearing 6, that is, the first side. The driving pulley 7 is fixed to the second side surface of the bearing 6.

  The rotating body side fastener 15 and the pulley fastener 16 are disposed on the same circumference. The rotating body side fasteners 15 and the pulley fasteners 16 are alternately arranged at equal intervals in the circumferential direction. The stationary frame side fastener 14 is disposed at the same position as the pulley fastener 16 in the circumferential direction of the rotating body 5.

  The rotating body 5 has an opposing portion 5b opposed to the end face 1a of the stationary frame 1 orthogonal to the axial direction of the rotating body 5 with a gap 17 therebetween. As shown in FIG.1 and FIG.5, the some through-hole 5c is provided in the opposing part 5b. Each through hole 5 c is configured by a screw hole, and penetrates the opposing portion 5 b in parallel with the axial direction of the rotating body 5.

  The end surface 1a is provided with a plurality of rotating body fixing screw holes 1b. The rotating body fixing screw hole 1b is disposed at a position facing the through hole 5c of the end face 1a.

  At the time of replacing the bearing 6, the gap holding member (shaft) 18 as shown in FIG. 6 is attached to the through hole 5c of FIG. The gap holding member 18 is constituted by a cylindrical male screw, and a hole 18 a is provided at the center. That is, the outer periphery of the gap holding member 18 is threaded.

  Next, a method of replacing the bearing 6 according to the first embodiment will be described with reference to FIGS. 7 to 11. First, as shown in FIG. 7, the gap holding member 18 is screwed into the through hole 5 c and attached to the rotating body 5. At this time, the gap 17 is held by bringing the end of the gap holding member 18 into contact with the end face 1 a.

  Subsequently, the rotor fixing screw 19 is passed through the hole 18 a of the gap holding member 18 and screwed (tightened) into the rotor fixing screw hole 1 b. Thus, the rotating body 5 is fixed to the stationary frame 1 while maintaining the gap 17 between the end face 1 a and the facing portion 5 b.

  The outer ring 6a is provided with a hole 6g through which the tip of the rotating body fixing screw 19 penetrating the stationary frame 1 is released. Further, a space is provided between the inner periphery of hole 18a of gap holding member 18 and the outer periphery of rotating body fixing screw 19 to absorb an error in the position of rotating body fixing screw hole 1b with respect to the position of through hole 5c. It is done.

  Thereafter, as shown in FIGS. 8 and 9, the pulley fastener 16 is removed from the inner ring 6b, and the drive pulley 7 is removed from the bearing 6. Thereby, the stationary frame side fastener 14 can be exposed outside.

  Next, as shown in FIGS. 10 and 11, the stationary frame side fastener 14 is removed from the cylindrical portion 3 b, and the rotating body side fastener 15 is removed from the rotating body 5. At this time, since the rotating body 5 is fixed to the stationary frame 1 by the rotating body fixing screw 19, the bearing 6 can be removed. Therefore, the existing bearing 6 can be replaced with a new bearing.

  Thereafter, in the reverse procedure described above, a new bearing is fixed to the cylindrical portion 3 b by the stationary frame side fastener 14 and to the rotary body 5 by the rotary body side fastener 15. Further, the drive pulley 7 is fixed to a new bearing by the pulley fastener 16. Then, the gap holding member 18 and the rotating body fixing screw 19 are removed.

  In such an X-ray CT apparatus, the rotating body 5 is provided with the through hole 5c through which the gap holding member 18 passes when replacing the bearing 6, and the rotating body into which the rotating body fixing screw 19 is screwed when replacing the bearing 6. Since the fixed screw hole 1b is provided on the end face 1a, even if there is a gap 17 between the stationary frame 1 and the rotating body 5, the gap 17 can be held by a simple configuration to easily replace the bearing 6 can do.

  This makes it possible to reduce the backtracking of the manufacturing process and to shorten the replacement time of the bearing 6 at the installation facility of the X-ray CT apparatus. Furthermore, since the replacement of the bearing 6 at the site becomes easy, it becomes possible to use a relatively inexpensive bearing 6.

  Further, in the bearing replacement method of the first embodiment, the bearing 6 is replaced in a state where the rotating body 5 is fixed to the stationary frame 1 by the rotating body fixing screw 19 while holding the gap 17 by the gap holding member 18. With this configuration, the bearing 6 can be easily replaced.

  Furthermore, since the gap holding member 18 is constituted by a male screw, and the through hole 5c is constituted by a screw hole, the common gap holding member 18 is not dependent on the size of the gap 17 for each X-ray CT apparatus. Thus, the gap 17 can be easily held.

  Furthermore, since the gap holding member 18 is cylindrical and is provided with a hole for passing the rotating body fixing screw 19 at the center, the rotating body 5 can be fixed to the stationary frame 1 at the position holding the gap 17. By tightening the rotating body fixing screw 19, distortion of the rotating body 5 can be prevented.

  Further, since the stationary frame side fastener 14 and the rotating body side fastener 15 are respectively fastened to the stationary frame 1 and the rotating body 5 from the same direction in the axial direction of the rotating body 5, the bearing 6 can be removed and attached in the same direction. Work efficiency is improved.

  Furthermore, since the gap holding member 18 and the rotating body fixing screw 19 are made to pass through the through hole 5c from the direction opposite to the fastening direction of the stationary frame side fastener 14 and the rotating body side fastener 15, In the state which fixed the rotary body 5 to the stationary frame 1, the bearing 6 can be replaced easily.

  Furthermore, the bearing 6 and the driving pulley 7 can be attached from the same surface on one side of the stationary frame 1, and the assembling workability is improved.

  Further, the gap holding member 18 and the rotating body fixing screw 19 can be used not only at the time of replacement of the bearing 6 but also at the time of transfer, and the load on the bearing 6 due to the impact at the time of transfer can be reduced.

Second Embodiment
Next, FIG. 12 is a cross-sectional view of an essential part of an X-ray CT apparatus according to a second embodiment of the present invention, which is a cross-sectional view corresponding to FIG. In the second embodiment, the stationary frame side fastener 14 and the rotating body side fastener 15 do not penetrate the bearing 6. Instead, the bearing 6 is fixed by sandwiching the parts.

  Specifically, the outer ring 6 a is sandwiched between the cylindrical portion 3 b and the outer ring fixing plate 20. Further, the inner ring 6 b is sandwiched between the rotating body 5 and the driving pulley 7. Further, the driving pulley 7 is fixed to the rotating body 5 by the rotating body side fastener 15. The other configuration and the bearing replacement method are the same as in the first embodiment.

  Even with such a configuration, the bearing 6 is replaced only by fixing the rotating body 5 to the stationary frame 1 using the gap holding member 18 and the rotating body fixing screw 19 and removing the driving pulley 7 and the outer ring fixing plate 20. Thus, the same effect as that of the first embodiment can be obtained.

  In the above example, the rotating body fixing screw 19 and the gap holding member 18 are passed through the same through hole 5c, but the rotating body fixing screw 19 may be disposed at a position different from the gap holding member 18 in the circumferential direction. it can.

  Further, the rotating body fixing screw hole 1 b may not penetrate the stationary frame 1.

  Furthermore, in the above example, although the gap holding member 18 is configured by the male screw, for example, as shown in FIG. 13, the gap holding member 22 fixed to the rotating body 5 by a plurality of bolts 21 may be used. In this case, the through hole 5c does not have to be a screw hole.

  Furthermore, in the above example, the rotating body 5 is fixed to the cylindrical portion 3b of the stationary frame 1 when replacing the bearing 6, but may be fixed to other places of the stationary frame 1, for example, the side frames 4a and 4b.

  Further, in FIG. 1, devices such as the X-ray tube 8 and the X-ray detector 9 are mounted inside the rotating body 5, but the X-ray CT apparatus in which the devices are mounted outside the rotating body The invention is applicable.

  Reference Signs List 1 stationary frame, 1a end face, 1b rotating body fixing screw hole, 5 rotating body, 5b facing portion, 5c through hole, 6 bearing, 14 stationary frame side fastener, 15 rotating body side fastener, 17 gap, 18 and 22 gap retaining Member, 18a hole, 19 rotating body fixing screw

Claims (2)

A stationary frame, a rotating body rotatably supported by the stationary frame, rotating around the subject, a bearing interposed between the stationary frame and the rotating body, and the bearing A plurality of stationary frame side fasteners fixed to the frame, and a plurality of rotary body side fasteners fixing the bearing to the rotary body,
The rotating body has an opposing portion opposed to the end face of the stationary frame, which is orthogonal to the axial direction of the rotating body, with a gap therebetween,
The opposite portion is provided with a plurality of through holes,
A bearing replacement method for an X-ray CT apparatus, wherein a plurality of rotating body fixing screw holes are provided on the end face,
A step of holding the gap by attaching a plurality of gap holding members to the opposite portion in a state of being in contact with the end face through at least a part of the through holes;
Fixing the rotating body to the stationary frame by screwing a plurality of rotating body fixing screws into at least a part of the through holes into the rotating body fixing screw holes respectively;
Removing the stationary frame side fastener and the rotating body side fastener and replacing the existing bearing with a new bearing;
X-ray CT apparatus including a step of fixing the new bearing to the stationary frame and the rotating body by the stationary frame side fastener and the rotating body side fastener, and a step of removing the gap holding member and the rotating body fixing screw Bearing replacement method. Each of the gap holding members has a cylindrical shape with a hole at the center,
Bearing replacing the rotating member fixing screws through the holes of the gap retaining member screwed into the rotating body fixing screw holes Claim 1 X-ray CT apparatus according.

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